Electric water-heater.



J. MANN. 1 ELECTRIC WATER HEATER.

APPLICATION FILED MAY 6, 1913.

1,120,830. Patented Dec. 15, 1914.

T\ 5. Q 5 \"B A Q UNITED STATES PATENT onrron com: MANN, or KILBUBN, LONDON, ENGLAND.

ntncrmc WATER-HEATER.

To all whom-it may concern: I

Be it known that I, JOHN MANN, subject of the King of Great Britain and Ireland, residing, at 12 Kilburn S uare, Kilburn, London, in the county of 'ddlesex, Eng land, have invented certain new and useful Improvements in Electric Water-Heaters, of which the following is a specification. My invention relates to improvements in apparatus for heating water by electricity whereby burning or fusing of the resistance wires or filaments is prevented, and the heat generated by the current in the resistance wires or filaments is conserved so as to utilize the whole of same for heating the water without unnecessary waste.

In order to distinguish my invention from the previous attempts to economically heat water by electricity, I append a brief description of the methods and apparatus previously employed which are as follows (1) A coiled pipe through which the water passes is coated with vitreous enamel and a fine resistance wire is wound upon and embedded in the enamel on the pipe.

A handle both operates a valve to control the flow of the water and switches on and controls the current in the resistance wire so that the latter varies with the volume of water passing and is totally cut-off when the flow of water discontinues.

(2) An annular chamber hating a resistance wire through which an electric current may be passed, coiled within it, and from which the air is more or less exhausted, is entirely submerged in the water to be heated.

(3) A11 exhausted chamber has a series of tubes passing backward and forward along.

the length through which the water to be heated is passed. Electrical resistance wires are wound upon the exterior of these tubes.

'' A non-return valve has also been employed in a self contained apparatus to prevent the entrance of the liquid from the container to the top of the heating chamber but pernntting circulation between them.

though the chamber containing the heating Specification of'I-etters Patent.

Patented Dec. 15, 1914'.-

Application filed ma 6, 191s. Serial m- 765,731.

resistanceis totally' submerged in the water to be heated and consequently almost all the heat generated must be collected by the water; much heat will be lost by radiation and conduction from the water itself which has'large surfaces exposed; in the third, the multiplicity of joints required to be made and maintained, causes undue difiiculties and expense 1n the manufacture and renders the apparatus proportionately liable to break down.

Now to overcome the dificulties experienced with the foregoing apparatus I employ a copper or other tube bent to form a tubular helical coil through which the water passes. Around the tube which forms the helical coil and suitably insulated from it, is wound the resistance Wire. This coil is placed within a suitable metal, glass, enameled clay or other cylinder or like container which is exhausted of air or other gases, so as to produce a vacuum therein. Suitable insulated terminals are provided on the cylinder .or like container, which are connected to the electrical resistance wires or filaments which are wound on the water carrying coil.

The upfiow of the tubular coil is fitted with a suitable check valve, so that when the fluid is being drawn ofi from the upfiow the check valve closes preventing communication therethrough: but should the current be left on while the exit from the upflow was closed the water in the coil would circulate from the reservoir or tank through the coil to the upflow and back to the reservoir or tank by way of check valve.

In order that my invention may be more readily understood, reference is had to the accompanying sheet of drawings.

Referring to the drawings A is the helical tubular coil having inflow and outflow ends A and A projecting through the cover 7; of the container B in which the coil is situated. Resistance wires or filaments C are wound uponthe tube forming the helical coil and connected to the terminals 0 on the cover 12. On the upflow pipe is situated the draw ofi' cock a and a check valve a provided between it and the reservoir to allow circulation from the reservoir through the coil and back to the reservoir when the draw off cook a is closed, and to prevent water being drawn direct from the reservoir when it is open. The container B which is exhaustcover I) by screws 6 by removing which the container and cover may be separated and the whole of the coil and; its winding exposed for examination or repair. Y

5 What I claim as my invention and desire to secure by Letters Patent is An electric water heater comprising th combination of a heating element consisting of a plate in which is fixed a helical tubular 10 coil,-the two ends of whichextend through the plateon one side, forming an inlet and outlet to and from the'coil, which coil is on the other side of the plate, an electric resistance Wound upon said coil, two insulating 15 plugs in said plate, each of which is fitted with a terminal, the ends of said resistance being attached to said terminals, a draw ofi' d cock upon the outlet end of said tubular coil 7 and a one way valve in said outlet pipe beyond said draw 05 cock, with a cup shaped :29

casing fitting over said tubular helicalcoil on to said plate with a gas tight joint, forming a chamber from which air, and other gas is removed as set forth.

In witness whereof I have hereunto set 25 

